This invention relates to protecting copper articles from a corrosive environment, and in particular, to protecting copper heat exchangers used in refrigerated cargo containers.
Ocean going cargo ships now carry large containers on their open decks which serve to expand the ship's utility. Many of these containers are equipped with refrigeration systems so that they can store perishable goods for relatively long periods of time. The refrigeration systems, however, are exposed to salt, air and water which causes the exposed parts to corrode at an accelerated rate. Heat exchanger surfaces used in the refrigeration systems are particularly susceptible to salt air and salt water corrosion.
In an effort to combat the harmful effects of salt, air and water, heat exchangers used in sea going containers are typically fabricated of copper. In addition, exposed surfaces of the heat exchangers have also been coated with various types of paints for added protection. These protective coatings have met with only with limited success for a number of reasons. First, most coating materials do not adhere well to copper and eventually the coating will flake away to expose the copper substrate. Secondly, the coating must be relatively thin so that it does not adversely effect the heat transfer characteristics of the heat exchanger. Most thin layer coatings, however, are extremely porous and thus will not establish an impenetrable protective barrier for the underlying copper.
As will be described in greater detail below, the present invention will be explained with specific reference to providing a protective barrier for a copper heat exchanger. However, it should be evident to one skilled in the art that the invention is not limited to this specific application and can be used in connection with any copper article where the need exists to protect the article from a hostile environment or the like.